The nurse is completing an admission assessment on an older adult client with dehydration, failure to thrive, and who is immobile. The nurse reports to the healthcare provider that the client's right calf is red and swollen. The nurse should suspect which probable cause of these findings?

A. Infection: While infection can cause localized redness and swelling, deep vein thrombosis (DVT) is a more likely cause given the client's immobility and other risk factors. B. Fat emboli: Fat emboli typically occur after trauma or orthopedic procedures, and their presentation is less likely in this scenario. C. Pulmonary embolism: While a pulmonary embolism is a potential complication of DVT, it presents with symptoms such as dyspnea, chest pain, and tachypnea, rather than localized redness and swelling in the calf. D. Deep vein thrombosis: This condition, characterized by redness and swelling in the affected limb, is common in immobile patients and those with dehydration, making it the most likely cause of the client's symptoms.